Fixes bug in handling restacking because of transients

ui/aura/mus/window_port_mus.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_AURA_MUS_WINDOW_PORT_MUS_H_
 #define UI_AURA_MUS_WINDOW_PORT_MUS_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 95 matching lines @@
   //     window_tree_client_->OnFooChanged(this, ...);
   enum ServerChangeType {
     ADD,
     ADD_TRANSIENT,
     BOUNDS,
     DESTROY,
     PROPERTY,
     REMOVE,
     REMOVE_TRANSIENT,
     REORDER,
+    // This is used when a REORDER *may* occur as the result of a transient
+    // child being added or removed. As there is no guarantee the move will
+    // actually happen (the window may be in place already) this change is not
+    // automatically removed. Instead the change is explicitly removed.
+    TRANSIENT_REORDER,
     VISIBLE,
   };
 
   // Contains data needed to identify a change from the server.
   struct ServerChangeData {
-    // Applies to ADD, ADD_TRANSIENT, REMOVE, REMOVE_TRANSIENT and REORDER.
+    // Applies to ADD, ADD_TRANSIENT, REMOVE, REMOVE_TRANSIENT, REORDER and
+    // TRANSIENT_REORDER.
     Id child_id;
     // Applies to BOUNDS.
     gfx::Rect bounds;
     // Applies to VISIBLE.
     bool visible;
     // Applies to PROPERTY.
     std::string property_name;
   };
 
   // Used to identify a change the server.
   struct ServerChange {
     ServerChangeType type;
     // A unique id assigned to the change and used later on to identify it for
     // removal.
     ServerChangeIdType server_change_id;
     ServerChangeData data;
   };
 
+  using ServerChanges = std::vector<ServerChange>;
+
   // Convenience for adding/removing a ScopedChange.
   class ScopedServerChange {
    public:
     ScopedServerChange(WindowPortMus* window_impl,
                        const ServerChangeType type,
                        const ServerChangeData& data)
         : window_impl_(window_impl),
           server_change_id_(window_impl->ScheduleChange(type, data)) {}
 
     ~ScopedServerChange() { window_impl_->RemoveChangeById(server_change_id_); }
@@ skipping 18 matching lines @@
                                     const ServerChangeData& data);
 
   // Removes a ServerChange by id.
   void RemoveChangeById(ServerChangeIdType change_id);
 
   // If there is a schedule change matching |type| and |data| it is removed and
   // true is returned. If no matching change is scheduled returns false.
   bool RemoveChangeByTypeAndData(const ServerChangeType type,
                                  const ServerChangeData& data);
 
+  ServerChanges::iterator FindServerChangeByTypeAndData(

[msw, 2016/11/21 19:56:34]

nit: nix 'Server' here or add to functions above?

[sky, 2016/11/21 21:31:43]

Done.

+      const ServerChangeType type,
+      const ServerChangeData& data);
+
   PropertyConverter* GetPropertyConverter();
 
   // WindowMus:
   Window* GetWindow() override;
   void AddChildFromServer(WindowMus* window) override;
   void RemoveChildFromServer(WindowMus* child) override;
   void ReorderFromServer(WindowMus* child,
                          WindowMus* relative,
                          ui::mojom::OrderDirection) override;
   void SetBoundsFromServer(const gfx::Rect& bounds) override;
   void SetVisibleFromServer(bool visible) override;
   void SetOpacityFromServer(float opacity) override;
   void SetPredefinedCursorFromServer(ui::mojom::Cursor cursor) override;
   void SetPropertyFromServer(
       const std::string& property_name,
       const std::vector<uint8_t>* property_data) override;
   void SetSurfaceIdFromServer(
       std::unique_ptr<SurfaceInfo> surface_info) override;
   void DestroyFromServer() override;
   void AddTransientChildFromServer(WindowMus* child) override;
   void RemoveTransientChildFromServer(WindowMus* child) override;
   ChangeSource OnTransientChildAdded(WindowMus* child) override;
   ChangeSource OnTransientChildRemoved(WindowMus* child) override;
   std::unique_ptr<WindowMusChangeData> PrepareForServerBoundsChange(
       const gfx::Rect& bounds) override;
+  void PrepareForTransientRestack(WindowMus* window) override;

[msw, 2016/11/21 19:56:34]

nit: order these just after PrepareForServerVisibilityChange

[sky, 2016/11/21 21:31:43]

Done.

+  void OnTransientRestackDone(WindowMus* window) override;
   std::unique_ptr<WindowMusChangeData> PrepareForServerVisibilityChange(
       bool value) override;
   void NotifyEmbeddedAppDisconnected() override;
 
   // WindowPort:
   void OnPreInit(Window* window) override;
   void OnDeviceScaleFactorChanged(float device_scale_factor) override;
   void OnWillAddChild(Window* child) override;
   void OnWillRemoveChild(Window* child) override;
   void OnWillMoveChild(size_t current_index, size_t dest_index) override;
   void OnVisibilityChanged(bool visible) override;
   void OnDidChangeBounds(const gfx::Rect& old_bounds,
                          const gfx::Rect& new_bounds) override;
   std::unique_ptr<WindowPortPropertyData> OnWillChangeProperty(
       const void* key) override;
   void OnPropertyChanged(const void* key,
                          std::unique_ptr<WindowPortPropertyData> data) override;
 
   WindowTreeClient* window_tree_client_;
 
   Window* window_ = nullptr;
 
   ServerChangeIdType next_server_change_id_ = 0;
-  std::vector<ServerChange> server_changes_;
+  ServerChanges server_changes_;
 
   SurfaceIdHandler* surface_id_handler_;
   std::unique_ptr<SurfaceInfo> surface_info_;
 
   ui::mojom::Cursor predefined_cursor_ = ui::mojom::Cursor::CURSOR_NULL;
 
   DISALLOW_COPY_AND_ASSIGN(WindowPortMus);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_MUS_WINDOW_PORT_MUS_H_